138128647 has 2 divisors, whose sum is σ = 138128648. Its totient is φ = 138128646.

The previous prime is 138128633. The next prime is 138128657. The reversal of 138128647 is 746821831.

138128647 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138128647 - 2²⁷ = 3910919 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138128657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69064323 + 69064324.

It is an arithmetic number, because the mean of its divisors is an integer number (69064324).

Almost surely, 2^138128647 is an apocalyptic number.

138128647 is a deficient number, since it is larger than the sum of its proper divisors (1).

138128647 is an equidigital number, since it uses as much as digits as its factorization.

138128647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 40.

The square root of 138128647 is about 11752.8144288932. The cubic root of 138128647 is about 516.9254556949.

The spelling of 138128647 in words is "one hundred thirty-eight million, one hundred twenty-eight thousand, six hundred forty-seven".